1. Field of the Invention
The present invention relates to a torsional vibration damper for coupling a turbine wheel hub with a turbine wheel shell in a hydrodynamic clutch device and/or for coupling a lockup clutch arrangement with a turbine wheel, the torsional vibration damper including a primary side and a secondary side which is rotatable about an axis of rotation with respect to the primary side against the action of a damper element arrangement, and a radial bearing arrangement for supporting the primary side and secondary side with respect to one another in radial direction.
2. Description of the Related Art
German reference DE 197 24 973 C1 discloses a torsional vibration damper in which the primary side and the secondary side of the torsional vibration damper comprise various subassemblies of a turbine wheel hub. That is, a first subassembly part of the turbine wheel hub, which is associated with the turbine wheel shell with respect to rotary operation since it is fixedly connected therewith, is connected with one of the primary and secondary side so as to be fixed with respect to rotation relative to it, and a second subassembly part of the turbine wheel hub is connected with the other side of the primary and secondary side so as to be fixed with respect to rotation relative to it or is constructed integral therewith. These two subassemblies or structural component parts are supported against one another in the radial direction by a radial bearing arrangement. Accordingly, the primary side and the secondary side of the torsional vibration damper with which these individual parts or subassemblies are associated are also supported with respect to one another in this way in radial direction by this radial bearing arrangement. The radial bearing is located in an area close to the axis of rotation. Due to the small radial distance from the axis of rotation, the bearing surface of the respective subassembly available for bearing support is very limited. The bearing surface of the respective subassembly is further limited by the axial extension.
In torsional vibration dampers of this kind, the relative rotation between the primary side and the secondary side of the torsional vibration dampers and the subassemblies which are supported against is in a small angular area of rotation with high frequencies with respect to one another. However, this results in a relatively small surface region of the surfaces or components used for mutual radial bearing support being passed over. In torsional damping operation, a very highly concentrated load occurs in this region or in these regions.
It is the object of the present invention to provide a torsional vibration damper having a primary side and a secondary side arranged so that the load occurring in vibration damping operation is reduced in a region used for radial bearing support between the primary side and the secondary side.
The object is met according to an embodiment of the present invention by a torsional vibration damper for coupling a turbine wheel hub with a turbine wheel shell and/or for coupling a lockup clutch arrangement with a turbine wheel in hydrodynamic clutch device. The torsional vibration damper includes a primary side and a secondary side which is rotatable about an axis of rotation with respect to the primary side against the action of a damper element arrangement. The torsional vibration element further comprises a radial bearing arrangement for supporting the primary side and secondary side with respect to one another in radial direction.
Furthermore, the radial bearing arrangement is arranged radially outside of the damper element arrangement.
Accordingly, the solution adopted by the present invention is to locate the radial bearing arrangement radially outward from the region utilized in the prior art, so that an appreciably greater surface region is provided for mutual support due to the larger radial distance from the axis of rotation with the same relative rotational angle between the primary side and secondary side. Consequently, the load concentration which occurs in the prior art is reduced and excessive wear in the region of the subassemblies used for mutual radial bearing support of the primary side and secondary side may be prevented.
A radial bearing arrangement which operates with particularly low wear may be achieved in that the radial bearing arrangement includes a plurality of bearing roller elements rotatably arranged at one side of the primary side and secondary side. The other side of the primary side and secondary side is movable relative to the one side and a plural bearing roller elements via a bearing surface.
In this embodiment, at least one bearing roller element is preferably mounted so as to be rotatable with respect to the one side of the primary side and secondary side via at least one bearing body. The at least one bearing body may be a sliding bearing body constructed as a sliding bearing sleeve supported at a bearing journal of the one side of the primary side and secondary side and on which a respective bearing roller element is supported.
In an alternative embodiment, at least one bearing roller element is mounted at a bearing journal of one side of the primary side and secondary side by a plurality of rolling bodies such as, for example, balls.
Another alternative embodiment of a torsional vibration damper according to the invention includes a plurality of sliding bearing elements arranged at one side of the primary side and secondary side. The other side of the primary side and secondary side is movable at these sliding bearing elements via a bearing surface.
To ensure that the primary side and the secondary side are movable with respect to one another only in a limited angle of relative rotation without excessive loading of the damper element arrangement, a circumferential movement stop is provided for a respective bearing roller element or sliding bearing element in at least one circumferential area when a bearing surface is associated with the respective bearing roller element or sliding bearing element.
The construction of a torsional vibration damper according to the invention is simplified by integration of functions or subassemblies in that a respective bearing surface is provided at a radial outer region of a supporting area serving to support the damper element arrangement at the other side of the primary side and secondary side.
In another alternative embodiment of the torsional vibration damper according to the present invention, the radial bearing arrangement comprises a bearing member which encloses the axis of rotation annularly and acts at a respective bearing surface of the primary side and secondary side. The bearing member preferably comprises a sliding bearing sleeve.
In an embodiment of the torsional vibration damper according to the present invention which is especially suited to torque transmission in the circumferential direction, the primary side includes two cover disk elements arranged at an axial distance from one another and fixedly connected with one another and the secondary side includes a central disk element arranged between the two cover disk elements.
To achieve an integration of functions or subassemblies in this case also and to simplify the construction as much as possible, the at least one bearing roller element or the at least one sliding bearing element is supported at a connection element connecting the cover disk elements with one another.
The turbine wheel shell of the hydrodynamic clutch device may be connected to a radially inner region of at least one of the cover disk elements. The turbine wheel hub of the hydrodynamic clutch device may then be connected with the central disk element. Furthermore, the turbine wheel hub may form one part with the central disk element.
Further, a clutch element of a lockup clutch of the hydrodynamic clutch device may be connected with the primary side of the torsional vibration damper. The clutch element may comprise a plate carrier and may be held at the primary side via connection elements.
The present invention is further directed to a hydrodynamic clutch device such as a hydrodynamic torque converter or a fluid coupling with a torsional vibration damper according to the present invention.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.